Gem Inclusion Pairs • Hyperion Siamese Twins

by Lotus Gemology

Why should Hugh Hefner be the only one who has enjoyed twins? This special Hyperion Inclusion Gallery features images contained in the Lotus Gemology Hyperion Inclusion Database, but are shown as pairs so that one can directly compare details like changes in lighting and treatments.

It would be both an identical work of art only by virtue of its difference.
The same but different, he suggested, like twins.Johnny Rich, The Human Script

Left: When viewed in transmitted light, this negative crystal within an untreated Sri Lanka padparadscha displays a hexagonal plate of graphite, along with a needle of diaspore. The undamaged nature of the negative crystal and diaspore needle confirms that the gem has not been heat treated.Right: Using overhead reflected light on the same negative crystal, one can see the high-relief of the hexagonal plate of graphite. The diaspore needle has a refractive index quite close to the surrounding corundum, and so "disappears" into the corundum matrix. The undamaged nature of the negative crystal and diaspore needle confirms that the gem has not been heat treated. Photos: Richard W. Hughes

Left: This red spinel from Tanzania’s Mahenge mines showed an unusual orange coloration surrounding a fingerprint inclusion.Right: When examined in oblique fiber-optic lighting, the orange area displays milky bluish clouds. This unmasks the orange color as a function of scattering, the same phenomena that creates a blue sky and orange sunset. Photos: Richard W. Hughes

Left: In this heated and fissure-healed ruby from Myanmar, a surface cavity is filled with glass. The glass can be identified by the gas bubble at the lower part of the cavity. Right: The same cavity when viewed with diffuse over head illumination, which clearly reveals its extent. The glass can be identified by its lower luster. Photos: Richard W. Hughes

Left: Demonstrating that the inner world can be as captivating as that outside, this Madagascar sapphire displays a small fingerprint scar with a beguiling moiré pattern. The undamaged nature of this inclusion testifies to the natural, untreated origin of the gem. Photo: E. Billie HughesRight: In this sapphire from Sri Lanka, evidence of high temperature heat treatment can be found in this moiré-patterned fingerprint. The once-lovely lacy pattern of liquid droplets is now besmirched by circular “explosions,” where the pressure from heating caused ruptures in the microscopic negative crystals, thus deflowering Mother Nature’s exquisite work of art. Photo: Richard W. Hughes

Left: This image clearly illustrates what master photomicrographer John Koivula has termed “chromophore cannibalization.” As titanium is drawn out of solid solution to form exsolved rutile silk, the area in the immediate vicinity is decolorized, losing its blue color. This is a natural process and is the reverse of “internal diffusion,” where heat treatment sends the titanium back into solution, creating blue clouds or “inkspots” around the rutile remnants. Photo: E. Billie HughesRight: When a rutile-silk containing sapphire is artificially heated, titanium from the rutile dissolves into the surrounding sapphire. Once in solid solution, the titanium reacts with iron, creating a blue color. The result is tiny blue halos surrounding the remnants of the rutile silk, a process dubbed “inkspot internal diffusion” by John Koivula. This partially dissolved silk with blue color concentrations is a clear sign that the sapphire was heated and is the opposite of chromophore cannibalization. Photo: Richard W. Hughes

Left: In this heated sapphire, one can clearly see “ink spot” internal diffusion, caused when the heat treatment partially dissolves the rutile silk, sending titanium into solid solution. This is a sure sign of high-temperature heat treatment. Check the next photo for the appearance in short-wave ultraviolet light. Photo: Richard W. HughesRight: Using a powerful short-wave ultraviolet light, one can see a chalky fluorescence in the same pattern. It is the colorless, rather than blue areas, that fluoresce. Photo: E. Billie Hughes

Left: Unusual birefringent crystals in a low-relief partially healed fissure in a sapphire treated with high-temperature heat plus modest pressure (HT+P). When tested with Lotus Gemology’s microraman, they proved to be corundum. It is thought that they crystallized during the treatment process. FOV 4 mm.Right: When viewed between crossed polars, the crystals stand out much more clearly. Photos: E. Billie Hughes

From Top Left to Right: Secondary healed fissures in corundum are often filled with carbon dioxide, but usually in liquid form (solid carbon dioxide is what we know as “dry ice”). On occasion we see it in both liquid and gaseous form. This series of four images shows liquid carbon dioxide with a gas bubble (the yellow area). As the heat of the microscope warms the specimen, the gas bubble shrinks and eventually disappears. The critical temperature at which the phase changes is 31.2°C. The existence of carbon dioxide inclusions in sapphire was first noted by David Brewster in 1826. He also noted the explosive nature of such inclusions, which burst at temperatures generally between 250–400°C. Photos: Richard W. Hughes

Left: Many crystals contain shallow fissures on their surfaces. In sapphires from Sri Lanka, Myanmar and Madagascar, these fissures often contain epigenetic yellow stains caused by deposits from Fe-rich fluids. Right: High-temperature heating not only destroys the yellow stains, but begins a process of healing, where the fissures turn white and start forming fingerprints, as we can see here. Note that such yellow stains are generally missing in the fissures of Kashmir sapphires. Photos: Richard W. Hughes

Left: Overhead lighting was used to photograph this scene in a violet sapphire from Sri Lanka, which shows two large mica plates. The undamaged state of the mica reveals that this sapphire has not been subjected to heat treatment.Right: A combination of dark field and overhead lighting was used to photograph the same scene as at left, revealing two large mica plates and smaller rounded zircon crystals. The undamaged state of the mica reveals that this sapphire has not been subjected to heat treatment. Photos: Richard W. Hughes

Left: In this flattened negative crystal in a Sri Lankan padparadscha sapphire, multiple phases can be found, including both liquid and gaseous carbon dioxide and a diaspore needle. Because diaspore’s refractive index (nα = 1.682–1.706; nβ = 1.705–1.725; nγ = 1.730–1.752) is so close to corundum (nω = 1.762; nε = 1.770) the diaspore needle almost disappears into the sapphire, appearing like a narrow indentation into the negative crystal. Liquid carbon dioxide becomes a gas at a fairly low temperature, with just the heat of the microscope causing the bubble to disappear. Intact negative crystals such as this are positive proof that the specimen has not been heat treated.Right: Reflected light reveals surface detail that is masked in transmitted light. Photos: Richard W. Hughes

Left: A fingerprint with many small negative crystal channels showing no signs of heat-induced damage in a sapphire from Madagascar.Right: In this heat-altered fingerprint, one can clearly see that each of the negative crystal channels has burst from the heat treatment. Also note the glassy circular "discoid" fissures. Photos: E. Billie Hughes

Left: Brown monazite crystals are sometimes found in sapphires from Madagascar’s Ilakaka region. In this gem one can see glassy tension halos around each, indicating that the gem was subjected to low temperature (less than 1400°C) heat treatment.Right: When viewed with dark-field illumination, the glassy tension halos around each monazite crystal are more distinct. Photos: E. Billie Hughes

Left: A heat-altered crystal with an iridescent decrepitation halo, alongside a surface cavity filled with glass.Right: When the direction of the reflected light is changed to show the surface, it reveals patches of glass on the surface (right). Photos: Richard W. Hughes

Left: When a crystal is heated (either by a magma or artificially by human intervention), it expands. Tension is often relieved by a fissure in the weakest direction, which in corundum is in the basal plane. Such fissures are difficult to see in dark-field illumination.Right: If the lighting is changed from dark field to overhead fiber-optic, the flat tension disc appears in dramatic relief. This example is in a heat-treated blue sapphire from Bo Ploi (Kanchanaburi), Thailand. Such inclusions are quite common in both rubies and sapphires recovered from magmatic sources. Photos: Richard W. Hughes

Left: Kashmir sapphires are unique in that the skin of many crystals feature deep blue spots of color, like spots on a leopard’s back.Right: These blue spots are sometimes incorporated into finished stones, where they will be found just below the surface. Photos: Richard W. Hughes

Left: Secondary "fingerprint" in a Mong Hsu (Myanmar) ruby before heating. Note the angular nature of the negative crystal channels.Right: Following heat treatment with flux, one can see the "necking down" and rounding of the channels. For more on this, see "Fluxed Up: The Fracture Healing of Ruby." Photos: Richard W. Hughes

Left: A lovely rosette inclusion surrounds a mica crystal in this ruby from Mozambique’s Montepuez region. This “rosette” actually consists of negative crystals flattened in the plane of basal pinacoid (perpendicular to the c axis). Oblique fiber-optic lighting.Right: When viewed with dark field and oblique fiber-optic illumination, the appearance changes dramatically, illustrating the importance of utilizing various illumination techniques with the microscope. Photos: Richard W. Hughes

Left: Mozambique silk before heating shows a high luster rutile needle and an attached lower luster daughter crystal.Right: When such a stone is heated to a high enough temperature, the daughter crystal begins to break down. Photos: E. Billie Hughes & Richard W. Hughes

Left: Undissolved rutile silk in sapphire. This forms along three directions, intersecting at 60/120° in the plane of the basal pinacoid (perpendicular to the c axis).Right: When a rutile silk-bearing sapphire is heated at a high temperatures (1400°C or more), the titanium quickly moves into solid solution, while other impurities (such as iron) do not, leaving behind silk skeletons. Photos: Richard W. Hughes

Left: Negative crystals in an untreated Mogok, Myanmar (Burma) sapphire in transmitted light. Right: When illuminated with a fiber optic light from above, small exsolved plates become visible, in addition to the negative crystals. Photos: E. Billie Hughes

Left: Transparent crystals, seen at left in transmitted light, can be hard to distinguish from negative crystals. Right: However when observed between crossed polars (right), the interference colors reveal their doubly refractive nature. Untreated sapphire from Sri Lanka. Photos: E. Billie Hughes

Left: With oblique fiber optic illumination, primary rutile crystals in an untreated Madagascar ruby show a dark red color.Right: In reflected light, we can also see that they display a submetallic luster where they were cut through on the surface. Photos: Richard W. Hughes

Left: This ruby from Madagascar contains a large cavity with a mobile CO2 bubble.Right: As the gem is rotated in the stoneholder, the bubble moves. Such fluid-filled cavities (generally filled with liquid and gaseous CO2) cannot withstand heat treatment and thus are proof of natural origin. Photos: E. Billie Hughes

Left: Birefringent crystals light up in different colors in this sapphire from Sri Lanka when viewed between crossed polars.Right: Note the change in appearance of the included crystals when viewed between parallel polars. Photos: E. Billie Hughes

Left: Laser-Induced-Breakdown-Spectroscopy (LIBS) is used by some gem labs to test for beryllium. Unlike Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICPMS), the surface is actually melted (rather than ablated), producing the circular rippled mark we see in the center of the girdle on the stone at left.Right: In contrast, LA-ICPMS ablates the gem, producing the symmetrical holes we see in the image at right. Photos: Richard W. Hughes & E. Billie Hughes